PROCESS AND APPARATUS FOR ENHANCING DISTRIBUTION OF NOX-REDUCING CHEMICALS IN A HIGH-SOLIDS ENVIRONMENT

摘要

Reduction of nitrogen oxides emissions from large scale combustors, such as coal-fired boilers and incinerators which produce effluents with high solids concentrations, is improved. High solids loading and other operational factors can cause such large temperature gradients transverse to the direction of effluent flow the SNCR cannot be practiced in conventional fashion. The process entails defining a near-wall zone having a temperature effective for SNCR and a central zone where the temperature is too high. NOx-reducing composition is introduced into the effluent within the near-wall zone in fine droplets (30 and 130) and can be introduced into the central zone after the gas has cooled or as large droplets effective to survive the high temperature.